Process control alarm systems are used in the area of factory automation. Specifically, process automation uses many process control alarms to inform operators that a process is within or has exceeded process control tolerance limits. A typical application in which a process control alarm system is employed is a styrene manufacturing plant. Within a styrene manufacturing plant, various manufacturing processes require machines and equipment, such as a feed tankage system, furnace, heat recovery system, one or more reactors, and a separator. The number of process control alarms constantly monitoring these machines in a styrene manufacturing plant ranges in the hundreds, whereas in oil refineries, then number ranges in the tens of thousands. Each process control alarm generally has at least one associated process control alarm variable.
In the past, alarm displays have been large boards with lights and labels, where an illuminated light or LED indicates which process control alarm has sensed a problem in a machine, or which machine in the factory is experiencing a problem. Today, a software interface to aid operators in understanding what is happening with one or many machines is used rather than the alarm board. Increasingly, a GUI (Graphical User Interface) is used as the human-to-machine interface because of its inherent ease of use and intuitive qualities. Through a GUI interface, process control alarm monitor variables are often capable of being set and monitored. These process control alarm monitor variables are linked to one or more feedback systems used in a process control system to make pseudo real-time analysis possible.
A typical alarm system supports a set of standard (absolute and deviation) alarm conditions associated with several control block types. These control block types cause a corresponding indication in associated loop and process displays whenever an alarm condition occurs. In some alarm monitor systems, log displays augment the process displays and list a history of all alarms that have occurred in some interval of time, subject to a selection filter.
Alarms are a main automation system vehicle for dealing with operations too abnormal for automated accommodations. A large fraction of the abnormalities are effectively unfamiliar to an operations and applications group. Some abnormalities are very mild, but others are catastrophic. There are applications with thousands of potential alarms defined having hundreds of alarms active at any point in time, sometimes within a single causal shower.
A typical alarm system that provides alarm priority handling capabilities is inherently inadequate to support an operator in recognizing and coping with resulting abnormal or crisis situations. This is true under the best human factors support and applications design. An interest in operating with fewer operators places that much more of a load on the reduced number of operators, exacerbating the problem.
The prior art alarm monitoring systems fall short of providing an operator with a powerful means of accurately and insightfully diagnosing problems in a machine/process during a so-called alarm shower or, even, a static alarm situation. In patent application Ser. No. 09/303,519 filed Apr. 30, 1999 entitled xe2x80x9cAlarm Analysis Tools Method and Apparatusxe2x80x9d, the teachings of which are incorporated by reference in their entirety, an alarm monitoring system (referred to hereinafter as the previous system) (i) provides a powerful means for the operator to diagnose alarm situations, including alarm showers, and (ii) begins to optimize alarm diagnostic information by allowing an operator/system designer to group the alarms in an organized and meaningful manner. Once a hierarchically categorized and pattern-defined alarm monitoring system structure has been defined and is producing first order benefits in the areas of processing, filtering, and display, second order benefits may be leveraged on the defined structure of the monitoring system. Presently, the previous system stops short of providing second order benefits in selected areas of processing, filtering, and display. These second order benefits are described in Provisional Patent Application No. 60/123,215 filed Mar. 8, 1999 entitled xe2x80x9cFunctional Mask/Filter Elements and Apparatus,xe2x80x9d the entire teachings of which are incorporated herein by reference in their entirety.
In general, the present invention adds second order benefits to the previous alarm monitoring system that groups alarms into categorizations, categories, and patterns of alarm variables. Processing, mask/filter interfacing, control, and display capabilities are expanded. Some results of the second order benefits are improvements in overall look, feel, and control.
Second order benefits/improvements include improving descriptor summary processing, pattern recognition, mask/filtering, and displaying information. One word summary processing is improved for handling independent, related sets of events. xe2x80x9cOne wordxe2x80x9d summaries do not literally mean a single word summary, e.g., fuel tank; the term descriptor summary may be used to avoid confusion. Pattern recognition is improved by determining previously unidentified patterns from an alarm history log, then using the identified, previously unknown patterns in distinguishing these patterns from all of the other alarms and patterns occurring at the same time. Mask/filtering is improved by expanding masking based on functional considerations. Additionally, mask/filtering is improved by expanding the mask/filter modes for use with large numbers of nested categories. Finally, display capability is improved through additional selectors to calculated category displays.
The present invention includes a method and apparatus for recursively generating a one word summary for related independent events applied to an alarm monitoring system having categories and subcategories of alarms. The apparatus accesses alarm data that provides the states of the alarms. From the intersection between the states of the alarms and the total active alarms of an indicator category, a one word summary is computed to be the name of whichever one of a complete set of pre-configured categories of alarms has an intersection with the selected category which includes all of the same active alarms and the fewest other active or inactive alarmed variables. Then, based on alarm status for a subset of categories, the apparatus recursively determines one word summary categories for each one word summary category and subcategory. The result is one or more one word summaries for related, independent, alarm events.
The present invention also includes a method and apparatus for determining novel forms of patterns for future detection of the determined novel alarm patterns. A processor routine scans a historical database of alarm events for significant alarm events. By applying an auto-correlation technique across multiple significant alarm events, the processor routine determines novel forms of patterns of alarm events. Preferably, the processor routine employs time windows immediately after or optionally before the significant alarm events. The reason for using auto-correlation is that it restricts noise effects due to overlapping, unknown patterns. After the processor routine determines previously unrecognized alarm patterns, the processor routine applies the determined patterns of alarms to an alarm variable stream captured by the alarm monitoring system. In turn, the apparatus detects the determined novel forms of alarm patterns in the stream of alarm events.
The present invention also includes a method and apparatus for affecting reported information provided by an alarm monitoring system having categories and subcategories of alarms. Each category and subcategory includes related alarm variables having respective alarm and category status information. An alarm monitoring system displays in various screen views the plurality of alarm categories and subcategories and the alarm and category status information. Selectable functional mask/filter indicators are provided, where the functional mask/filter indicators represent possible functional states of the alarms. The alarm variables are mask/filtered across a subset of the alarm categories as a function of the state of the selectable functional mask/filter indicators. This affects the reported category alarm status information provided in the screen view.
The present invention also includes a method and apparatus for controlling and displaying mask/filter selections for an alarm monitoring system having hierarchically defined categories of alarms. A provided screen view displays a subset of categories expressed as category indications in a graphical user interface manner. Each category is a member of a categorization and includes subcategories and alarm variables, which represent corresponding alarm status information. The screen view includes mask/filter selectors, which are coupled to the category indications and a mask/filter. The mask/filter is coupled to the categorizations (and included categories, subcategories, and alarm variables), and the mask/filter selectors include an all-select selector and a so-called xe2x80x9cselectxe2x80x9d selector. The all-select selector enables an operator to select alarms in a specified category without regard to included, respective, subcategory, alarm selections. The select selector enables an operator to select alarms in a specified category, except for alarms not selected in included, respective, subcategory, alarm selections. The state of the mask/filter is changed in response to an operator""s selecting alarms at any hierarchical level (i.e., the processor routine modifies the underlying mask/filter bit string(s). Also, the processor routine visually modifies (as a function of the mask/filter) a subset of categorization, category, and alarm variable indications to provide mask/filter state information in the screen view, thereby displaying mask/filter selections.
The present invention also includes a method and apparatus for providing alarm information in an alarm analysis system having summary alarm status calculation capability. A first screen view displays at least one category of alarm information. For categories having a determinable one word summary for an overall alarm status within each category, a respective associated, dynamically computed, summary indicator describing the alarm status is presented to the operator. In response to an operator selection of a summary indicator, a second screen view is displayed having detailed information relating to the summary indicator. The second screen view thereby provides dynamic, detailed, alarm status information.